Sleep and Exercise

Contrary to common belief, exercising before bedtime does not disrupt sleep, recent studies have found. Finnish scientists monitored 11 young adults in a sleep laboratory. On one night, they instructed the volunteers to ride a stationary bike within three hours of bedtime until they were exhausted; on another night, everyone simply rested before bed. The participants had significantly higher heart rates during the night they exercised, but despite this physiological arousal, there was no apparent detriment to sleep quality—in fact, they fell asleep faster and had slightly more deep sleep. A Belgian study of nine volunteers who rode an exercise bike for 60 minutes within two hours of bedtime produced similar results. The research involved only people who generally had untroubled sleep, but late workouts might actually benefit people with mild sleep problems, says researcher Daniel Berckmans, a professor of bioscience engineering at Katholieke Universiteit Leuven, a university in Belgium. After engaging in physical activity, the body experiences faster heat loss, which helps speed up the onset of sleep, Berckmans explains.